Grandstream GBX20 Expansion Module Snom IP Phones Long Battery Life: The built-in

Long Battery Life: The built-in battery provides up to 20 hours of talk time and 167 hours of standby time

Advanced Features: Mac Address Auto-Learning And Auto-Aging

Extension Module:

server redundancy & fail-over

you are guaranteed not to miss any call

Grandstream GBX20 Expansion Module Snom IP Phones Long Battery Life: The built-inThe GBX20 is a backlit LCD extension module supported by the GRP2615, GRP2624, GRP2650, GRP2670 carrier grade IP phones as well as and GXV3350 and GXV3450 IP video phones. The module includes 20 dual colored extension keys and 2 arrow keys for page switching (allowing each GBX20 to support up to 40 contacts extensions). Connect up to 4 GBX20 modules to compatible Grandstream phones for a total of 160 contacts extensions. Features: 4. 3 inch (272480)